Hmm, I've been spotting a number of trigger plants in that area and always assumed the species is S.graminifolium. We had a discussion about the species (armeria or graminifolium) which Silke Smaglinski had registered on Mt Ainslie. Aaron, would you have the time to take a photo of the leaves?
I read the comments on sighting http://canberranaturemap.org/Community/Sightings/Details/1947895 detailing characteristics of Stylidium graminifolium and S. armeria, which seem at odds with the plant I have growing in my garden: it is labelled Stylidium graminifolium but has leaves 6 mm wide without hooked edges. I don't know if it is an out-of-town variation of a mislabelled plant.
The name Stylidium armeria was resurrected about 2004. Plantnet still only has the name, but no description. A lot of people have not caught up with the separation of these two species. Unfortunately I did not find the paper that separates the two species till we were in the final stages of preparing Flowers of the ACT and Region and found that we had a photo of Stylidium armeria and were at the wrong time of year to get one of Stylidium graminifolium on Black Mountain as well.